9.qt使用d3d

画三角形

main.cpp

#include <QApplication>
#include "D3DWidget.h"

int main(int argc, char* argv[]) {
    // 强制 Qt 不使用它默认的渲染器干扰原生绘制
    QCoreApplication::setAttribute(Qt::AA_DontCreateNativeWidgetSiblings);

    QApplication a(argc, argv);
    D3DWidget w;
    w.resize(800, 600);
    w.show();
    return a.exec();
}

D3DWidget.h

#pragma once
#include <QWidget>
#include <d3d11.h>
#include <wrl/client.h> // 使用 Microsoft::WRL::ComPtr 简化指针管理

using Microsoft::WRL::ComPtr;

class D3DWidget : public QWidget {
    Q_OBJECT
public:
    explicit D3DWidget(QWidget* parent = nullptr);
    ~D3DWidget() override;

protected:
    // 关键：重写这些以接管窗口控制权
    QPaintEngine* paintEngine() const override { return nullptr; }
    void paintEvent(QPaintEvent* event) override;
    void resizeEvent(QResizeEvent* event) override;

private:
    void initD3D();
    void render();

    ComPtr<ID3D11Device> m_device;
    ComPtr<ID3D11DeviceContext> m_context;
    ComPtr<IDXGISwapChain> m_swapChain;
    ComPtr<ID3D11RenderTargetView> m_renderTargetView;

    bool m_initialized = false;
    struct Vertex {
        float x, y, z;
        float r, g, b, a;
    };

    // 在 D3DWidget 类私有成员中添加：
    ComPtr<ID3D11VertexShader> m_vertexShader;
    ComPtr<ID3D11PixelShader> m_pixelShader;
    ComPtr<ID3D11InputLayout> m_inputLayout;
    ComPtr<ID3D11Buffer> m_vertexBuffer;
};

D3DWidget.cpp

#include "D3DWidget.h"
#include <QWindow>
#include <d3dcompiler.h>

// 另外，确保你也包含了 d3d11.h
#include <d3d11.h>
// 在 D3DWidget.cpp 顶部定义着色器源码
const char* g_shaderSource = R"(
struct VOut {
    float4 position : SV_POSITION;
    float4 color : COLOR;
};

VOut VShader(float4 position : POSITION, float4 color : COLOR) {
    VOut output;
    output.position = position;
    output.color = color;
    return output;
}

float4 PShader(float4 position : SV_POSITION, float4 color : COLOR) : SV_TARGET {
    return color;
}
)";
 
D3DWidget::D3DWidget(QWidget* parent) : QWidget(parent) {
    // 告诉 Qt 这是一个原生窗口，不要在上面做双缓冲绘制
    setAttribute(Qt::WA_PaintOnScreen);
    setAttribute(Qt::WA_NoSystemBackground);
}

D3DWidget::~D3DWidget() {}

void D3DWidget::initD3D() {
    DXGI_SWAP_CHAIN_DESC sd = {};
    sd.BufferCount = 1;
    sd.BufferDesc.Width = width();
    sd.BufferDesc.Height = height();
    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    sd.BufferDesc.RefreshRate.Numerator = 60;
    sd.BufferDesc.RefreshRate.Denominator = 1;
    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    sd.OutputWindow = (HWND)this->winId(); // 关键：绑定 Qt 句柄
    sd.SampleDesc.Count = 1;
    sd.SampleDesc.Quality = 0;
    sd.Windowed = TRUE;

    UINT createDeviceFlags = 0;
#ifdef _DEBUG
    createDeviceFlags |= D3D11_CREATE_DEVICE_DEBUG;
#endif

    D3D_FEATURE_LEVEL featureLevel;
    const D3D_FEATURE_LEVEL featureLevels[] = { D3D_FEATURE_LEVEL_11_0 };

    HRESULT hr = D3D11CreateDeviceAndSwapChain(
        nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, createDeviceFlags,
        featureLevels, 1, D3D11_SDK_VERSION, &sd,
        &m_swapChain, &m_device, &featureLevel, &m_context
    );

    if (SUCCEEDED(hr)) {
        m_initialized = true;
        resizeEvent(nullptr); // 触发第一次 RenderTarget 创建
    }

    // 1. 编译并创建着色器
    ComPtr<ID3DBlob> vsBlob, psBlob, errorBlob;

    // 编译顶点着色器
    D3DCompile(g_shaderSource, strlen(g_shaderSource), nullptr, nullptr, nullptr, "VShader", "vs_5_0", 0, 0, &vsBlob, &errorBlob);
    m_device->CreateVertexShader(vsBlob->GetBufferPointer(), vsBlob->GetBufferSize(), nullptr, &m_vertexShader);

    // 编译像素着色器
    D3DCompile(g_shaderSource, strlen(g_shaderSource), nullptr, nullptr, nullptr, "PShader", "ps_5_0", 0, 0, &psBlob, &errorBlob);
    m_device->CreatePixelShader(psBlob->GetBufferPointer(), psBlob->GetBufferSize(), nullptr, &m_pixelShader);

    // 2. 创建输入布局 (Input Layout)
    D3D11_INPUT_ELEMENT_DESC ied[] = {
        {"POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0},
        {"COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0},
    };
    m_device->CreateInputLayout(ied, 2, vsBlob->GetBufferPointer(), vsBlob->GetBufferSize(), &m_inputLayout);

    // 3. 创建顶点缓冲区
    Vertex vertices[] = {
        { 0.0f,  0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f }, // 顶点：红色
        { 0.45f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f }, // 右下：绿色
        {-0.45f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f }  // 左下：蓝色
    };

    D3D11_BUFFER_DESC bd = {};
    bd.Usage = D3D11_USAGE_DEFAULT;
    bd.ByteWidth = sizeof(vertices);
    bd.BindFlags = D3D11_BIND_VERTEX_BUFFER;

    D3D11_SUBRESOURCE_DATA srd = {};
    srd.pSysMem = vertices;
    m_device->CreateBuffer(&bd, &srd, &m_vertexBuffer);

    m_initialized = true;
}

void D3DWidget::resizeEvent(QResizeEvent* event) {
    if (!m_initialized) return;

    // 清理旧视图
    m_renderTargetView.Reset();

    // 调整 SwapChain 大小
    m_swapChain->ResizeBuffers(0, width(), height(), DXGI_FORMAT_UNKNOWN, 0);

    // 重新创建 RenderTargetView
    ComPtr<ID3D11Texture2D> backBuffer;
    m_swapChain->GetBuffer(0, IID_PPV_ARGS(&backBuffer));
    m_device->CreateRenderTargetView(backBuffer.Get(), nullptr, &m_renderTargetView);

    // 设置视口
    D3D11_VIEWPORT vp;
    vp.Width = (FLOAT)width();
    vp.Height = (FLOAT)height();
    vp.MinDepth = 0.0f;
    vp.MaxDepth = 1.0f;
    vp.TopLeftX = 0;
    vp.TopLeftY = 0;
    m_context->RSSetViewports(1, &vp);
}

void D3DWidget::paintEvent(QPaintEvent* event) {
    if (!m_initialized) initD3D();
    render();
}

void D3DWidget::render() {
    if (!m_initialized) return;

    // 清理背景
    float clearColor[] = { 0.0f, 0.2f, 0.1f, 1.0f };
    m_context->ClearRenderTargetView(m_renderTargetView.Get(), clearColor);

    // 设置渲染目标
    m_context->OMSetRenderTargets(1, m_renderTargetView.GetAddressOf(), nullptr);

    // 绑定着色器和布局
    m_context->VSSetShader(m_vertexShader.Get(), nullptr, 0);
    m_context->PSSetShader(m_pixelShader.Get(), nullptr, 0);
    m_context->IASetInputLayout(m_inputLayout.Get());

    // 绑定顶点缓冲区
    UINT stride = sizeof(Vertex);
    UINT offset = 0;
    m_context->IASetVertexBuffers(0, 1, m_vertexBuffer.GetAddressOf(), &stride, &offset);
    m_context->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);

    // 绘制！
    m_context->Draw(3, 0);

    m_swapChain->Present(1, 0);
    update();
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.20)
project(DrawOpenGL LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_AUTOMOC ON)

# 1. 查找 Qt6
find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)

# 2. 查找 Windows 系统 D3D 库
find_library(D3D11_LIB d3d11)
find_library(DXGI_LIB dxgi)
find_library(D3DCOMPILER_LIB d3dcompiler)

# 3. 添加源文件
add_executable(${PROJECT_NAME} 
    src/main.cpp 
    src/D3DWidget.h 
    src/D3DWidget.cpp
)

# 4. 链接所有库
target_link_libraries(${PROJECT_NAME} PRIVATE 
    Qt6::Core 
    Qt6::Gui 
    Qt6::Widgets
    ${D3D11_LIB} 
    ${DXGI_LIB} 
    ${D3DCOMPILER_LIB}
)

# 输出到项目下的 bin 文件夹
set_target_properties(${PROJECT_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/bin")